Electrical condenser



June '5, 1928.

1,671,996 E. L. POWELL ELECTRICAL CONDENSER Filed May 25, 1923 2 Sheets-Sheet l Edwin L. Powell.

June 5, 1928.

1,671,996 E. L. POWELL ELECTRICAL CONDENSER Filed ma 25, 1923 2 Sheets-Sheet 2 Edwin L. Powell Patented June 5, 1928.

UNITED STATES EDWIN L. IOWELL, OF WASHINGTON, DISTRICT OF COLUMBIA.

ELECTRICAL CONDENSER.

Application filed May 23,

My invention relates generally. to electrical condensers and more particularly to variable air condensers used in radio circuits.

I An object of the invention is to provide a condenser having dual control through a single knob.

A further object of the invention is to provide a condenser-permitting the greatest In economy in panel board space without complicating the movable plate control.

A still further object is to provide a condenser which reduces the cost manufacture to a minimum without sacrificing any of the In advantages of dual control.

With these and other objects in view the invention consists in the construction, combination and arrangement of parts as will be hereinafter described.

Reference is to be had to the accompanying drawings forming part of this specification, in which like reference characters indicate corresponding parts throughout the several views, and in which- Figure 1 is a plan view of my condenser,

Fig."2 is a cross sectional view thereof,

Fig. 3 is a section on the line 33 of Fig. 2, a

' Fig. 4 is a cross sectional view of a modi- 30 fied type, and

Fig. 5 is a section on the line 5-5 .of

Fig. 4.

Referring more particularly to Fig. 2 of the drawings, 5 indicates a panel board to which the condenser casing top 6 is attached by spacers 7. The usual movable plate assembly 8 and fixed plate assembly 9 are contained within the casing, the movable plates being secured to a spindle 10 which is provided with a recessed extension 11, and which supports a gear housing.

The gear housing comprises a top 12, a bottom 13, which is provided with a slot 14, the top and bottom being held in spaced relation by insulating spacers 15, and which is connected with a dial 16 movable within the panel 5, the panel being provided with an indicating mark to register with graduations on the dial to assist in obtaining 50' proper adjustment of the condenser plates.

A stud 17 passing through and secured to the top 6 is slidably engaged in the slot 14 and limits the movement of the adjustable plates.

A gear 18 fastened in any suitable manner to the extension of spindle 10 and to 1923. Serial No. 640,835.

' engages with gear 21.

The operating mechanism is normally in position for fine adjustment of the condenser plates through gears 25, 21, 20 and 18. Main adjustment is obtainable by pressing inwardly on the knob 24 disengaging gear 25 from gear 21 and causing pins 19 on gear 18 to become seated between the teeth of gear 25, as clearly shown in Fig. 3, thereby imparting direct motion to the gear 18 when knob '24 is rotated.

The construction illustrated in Fig. 4 is similar to that of Fig. 2, except that instead of using a gear with pins, a compound gear 28 is used. By compound gear I mean one having an extended tooth periphery 29 and an interiorly beveled hub portion 30. The

toothed periphery meshes with the gear 20 and the ub portion receives a beveled portion 31 of a member 32 which is provided with an external gear 33 engaging with gear 21. It will be understood that the beveled portions may be constructed for either friction, milled or toothed drive. When desired to change from fine to main adjustment pressure is exerted upon the knob which disengages gears 33 and 21 and seats the bevel 31 in the hub portion 30 of gear 28.

That the capacity effect of the body of the operator may be reduced to a minimum I find it desirable to ground the dial 16 to the panel 5 through a brush 34.

It is understood that the above description and accompanying drawings disclose only the preferred embodiments of my invention and that various minor changes in the detail of construction, proportion and arrangement of parts may be resorted to within the scope of the appended claims and without sacrificing any of the advantages of my invention.

Having fully described my invention,

what I desire to secure by Letters Patent 1. An electrical condenser including a movable and a fixed plate assembly, a shaft upon the movable plate assembly, a main adjustment gear upon said shaft, said gear being provided with co-axially extending projections, a fine adjustment gear train engaging said gear and means for engaging with the train of gears or the said projections for obtaining the desired adjustment.

2. An electrical instrument including a shaft, a movable member rotatable with 'said shaft, a fixed member, a train of gears, a gear fixedly secured to said shaft and engaging said train of gears, and a single means concentrically rotatable on and axially movable along said shaft to engage the train of gears or the gear upon the shaft for the desired adjustment of motion of said shaft.

3. In a device of the character described, the combination of a rotary knob or handle for manual operation, a shaft stopping short a distance from said handle and adapted to be adjusted, the knob being axially alined with said shaft, indicating means rigid with the shaft, a change speed gearing for connecting said knob or handle to said shaft, so that said shaft and knob will always each rotate in the same direction as the other, about a common axis, means whereby said knob or handle is movable axially to control said gearing, in changing from one speed to the other, and whereby said knob or handle is rotatable at a given speed in either direc-' tion to' rotate said shaft at the same speed, and so that said knob or handle is rotatable at the same speedto turn said shaft and its indicating means at a much slower speed to obtain delicate manual adjustment thereof.

4. A radio apparatus comprising anelement to be adjusted, indicating means rigid with said element, an adjusting knob or handle which can be operated by hand at a given speed to quickly move said radio instrument element and its indicating means from one position to another and which can be rotated at the same speed to thereafter move said element and its indicating means more slowly but in the same direction as the handle to ensure accurate tuning of the apparatus for the desired wave length, said handle or knob being rotatable, and said element being rotatable about the axis of said handle or knob, comprising means controlled by axial displacement of said handle or knob to change from one speed of adjustment to the other, so that said hand knob serves to transmit the power and also to control the change of speed.

5. An electrical instrument including a support, a shaft journalled within the support, a gear upon the shaft, a train of gears, one gear of the train of gears engaging the gear upon the shaft, and means movable position and for engaging the train of gears in its outer position for the indirect rotation of the shaft.

6. An electrical instrument including a support, a shaft journaled within the support, a gear upon the shaft, a train of gears, mounted upon the support, one gear of the train of gears engaging the gear upon the shaft, and means movable longitudinally of the shaft for engaging the shaft for the direct rotation thereof in its inner position and for engaging the train of gears in its outer position for the indirect rotation of the shaft, said means consisting of a member journaled upon the shaft, and a gear upon the inner end of the member.

7. An electrical instrument including a support, a shaft journaled within the support, a gear upon the shaft, a train of gears mounted upon the support, one gear of the I train of gears engaging the gear upon the shaft, and means movable longitudinally of the shaft for engaging the shaft for the direct rotation thereof in its inner position and for engaging the'train of gears in its outer position for the indirect rotation of the shaft and resilient means for maintaining the movable means in its outer position.

8. An electrical instrument including a support, a shaft journaled within the support, a gear upon theshaft, a train of gears mounted upon the support, one gear of the train of gears engaging the gear uponthe shaft, and means movable longitudinally of the shaft for engaging the shaft for the direct rotation thereof in its inner position and for engaging the train of gears in its outer position for the indirect rotation of the shaft and resilient means for maintaining the movable ;means in its outer position, said movable means consisting of a member journaled upon the shaft and a. gear upon the inner end of the member.

9. An electrical instrument including a support, a shaft journaled within the'support, a gear upon the shaft, a train of gears mounted upon the support, one gear of the train of gears engaging the gear upon the shaft, and means movable longitudinally of the shaft for engaging the shaft for the direct rotation thereof in its inner position and for engaging the train of gears in its outer position for the indirect rotation of the shaft and resilient means for maintaining the movable means in its outer position, said resilient means consisting of a spring within the member.

EDWIN L. POWELL. 

